#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
	int n,k;
	while(scanf("%d%d",&n,&k)!=EOF){
			if(n<k) cout<<2<<endl;
			else if(n*2%k==0) cout<<n*2/k<<endl;
			else cout<<n*2/k+1<<endl;
		
	}
}
